Erowid's estimated doses for 3-MeO-PCP are higher than the dose summaries provided by some other organizations. It is extremely important to note that strong or heavy doses of 3-MeO-PCP can cause powerful deleriant-type effects where the user is unaware that their perceptions, thoughts, and ideas are false or hallucinatory. Many people describe "psychosis"-like symptoms at doses in the strong and heavy range. When compared to ketamine, one of the primary differences is that people remain ambulatory (able to walk) at fully hallucinatory effects levels of 3-MeO-PCP.

In our review of reports, most people who like 3-MeO-PCP seem to report preferring light to common dose levels and avoid higher doses or mixing 3-MeO-PCP with sedatives, in order to avoid delusional, delirious states. While every individual reacts differently, the difference between 10 mg and 20 mg can be the difference between light euphoric inebriation and the delirious inability to tell whether a car is real or not.

Note that Bluelight's Big and Dandy 3-MeO-PCP Thread - Part 2 warns about risks of taking too much 3-MeO-PCP and suggests individuals should "slowly work [their] way up to about 10 mg, and only after considerable experience / expertise proceed to maybe 15 mg, with SMALL STEPS."

3-MeO-PCP is a dissociative. That means that what many people are looking for is an effect that is be experienced lying or sitting down. Doses as low as 10 or 15 mg in someone without tolerance could cause walking to be clumsy and potentially dangerous if unsupervised.